package org.apache.commons.lang.builder;

import java.util.Collection;

@SuppressWarnings("rawtypes")
public class EqualsBuilder {

	/**
	 * If the fields tested are equals. The default value is <code>true</code>.
	 */
	private boolean isEquals = true;

	/**
	 * <p>
	 * Constructor for EqualsBuilder.
	 * </p>
	 * <p>
	 * Starts off assuming that equals is <code>true</code>.
	 * </p>
	 * @see Object#equals(Object)
	 */
	public EqualsBuilder() {
		// do nothing for now.
	}

	// -------------------------------------------------------------------------

	/**
	 * <p>
	 * This method uses reflection to determine if the two <code>Object</code>s are equal.
	 * </p>
	 * <p>
	 * It uses <code>AccessibleObject.setAccessible</code> to gain access to private fields. This means that it will
	 * throw a security exception if run under a security manager, if the permissions are not set up correctly. It is
	 * also not as efficient as testing explicitly.
	 * </p>
	 * <p>
	 * Transient members will be not be tested, as they are likely derived fields, and not part of the value of the
	 * Object.
	 * </p>
	 * <p>
	 * Static fields will not be tested. Superclass fields will be included.
	 * </p>
	 * @param lhs <code>this</code> object
	 * @param rhs the other object
	 * @return <code>true</code> if the two Objects have tested equals.
	 */
	public static boolean reflectionEquals(Object lhs, Object rhs) {
		return reflectionEquals(lhs, rhs, false, null, null);
	}

	/**
	 * <p>
	 * This method uses reflection to determine if the two <code>Object</code>s are equal.
	 * </p>
	 * <p>
	 * It uses <code>AccessibleObject.setAccessible</code> to gain access to private fields. This means that it will
	 * throw a security exception if run under a security manager, if the permissions are not set up correctly. It is
	 * also not as efficient as testing explicitly.
	 * </p>
	 * <p>
	 * Transient members will be not be tested, as they are likely derived fields, and not part of the value of the
	 * Object.
	 * </p>
	 * <p>
	 * Static fields will not be tested. Superclass fields will be included.
	 * </p>
	 * @param lhs <code>this</code> object
	 * @param rhs the other object
	 * @param excludeFields Collection of String field names to exclude from testing
	 * @return <code>true</code> if the two Objects have tested equals.
	 */
	public static boolean reflectionEquals(Object lhs, Object rhs, Collection /* String */excludeFields) {
		throw new UnsupportedOperationException("reflectionEquals()");
	}

	/**
	 * <p>
	 * This method uses reflection to determine if the two <code>Object</code>s are equal.
	 * </p>
	 * <p>
	 * It uses <code>AccessibleObject.setAccessible</code> to gain access to private fields. This means that it will
	 * throw a security exception if run under a security manager, if the permissions are not set up correctly. It is
	 * also not as efficient as testing explicitly.
	 * </p>
	 * <p>
	 * Transient members will be not be tested, as they are likely derived fields, and not part of the value of the
	 * Object.
	 * </p>
	 * <p>
	 * Static fields will not be tested. Superclass fields will be included.
	 * </p>
	 * @param lhs <code>this</code> object
	 * @param rhs the other object
	 * @param excludeFields array of field names to exclude from testing
	 * @return <code>true</code> if the two Objects have tested equals.
	 */
	public static boolean reflectionEquals(Object lhs, Object rhs, String[] excludeFields) {
		return reflectionEquals(lhs, rhs, false, null, excludeFields);
	}

	/**
	 * <p>
	 * This method uses reflection to determine if the two <code>Object</code>s are equal.
	 * </p>
	 * <p>
	 * It uses <code>AccessibleObject.setAccessible</code> to gain access to private fields. This means that it will
	 * throw a security exception if run under a security manager, if the permissions are not set up correctly. It is
	 * also not as efficient as testing explicitly.
	 * </p>
	 * <p>
	 * If the TestTransients parameter is set to <code>true</code>, transient members will be tested, otherwise they are
	 * ignored, as they are likely derived fields, and not part of the value of the <code>Object</code>.
	 * </p>
	 * <p>
	 * Static fields will not be tested. Superclass fields will be included.
	 * </p>
	 * @param lhs <code>this</code> object
	 * @param rhs the other object
	 * @param testTransients whether to include transient fields
	 * @return <code>true</code> if the two Objects have tested equals.
	 */
	public static boolean reflectionEquals(Object lhs, Object rhs, boolean testTransients) {
		return reflectionEquals(lhs, rhs, testTransients, null, null);
	}

	/**
	 * <p>
	 * This method uses reflection to determine if the two <code>Object</code>s are equal.
	 * </p>
	 * <p>
	 * It uses <code>AccessibleObject.setAccessible</code> to gain access to private fields. This means that it will
	 * throw a security exception if run under a security manager, if the permissions are not set up correctly. It is
	 * also not as efficient as testing explicitly.
	 * </p>
	 * <p>
	 * If the testTransients parameter is set to <code>true</code>, transient members will be tested, otherwise they are
	 * ignored, as they are likely derived fields, and not part of the value of the <code>Object</code>.
	 * </p>
	 * <p>
	 * Static fields will not be included. Superclass fields will be appended up to and including the specified
	 * superclass. A null superclass is treated as java.lang.Object.
	 * </p>
	 * @param lhs <code>this</code> object
	 * @param rhs the other object
	 * @param testTransients whether to include transient fields
	 * @param reflectUpToClass the superclass to reflect up to (inclusive), may be <code>null</code>
	 * @return <code>true</code> if the two Objects have tested equals.
	 * @since 2.0
	 */
	public static boolean reflectionEquals(Object lhs, Object rhs, boolean testTransients, Class reflectUpToClass) {
		return reflectionEquals(lhs, rhs, testTransients, reflectUpToClass, null);
	}

	/**
	 * <p>
	 * This method uses reflection to determine if the two <code>Object</code>s are equal.
	 * </p>
	 * <p>
	 * It uses <code>AccessibleObject.setAccessible</code> to gain access to private fields. This means that it will
	 * throw a security exception if run under a security manager, if the permissions are not set up correctly. It is
	 * also not as efficient as testing explicitly.
	 * </p>
	 * <p>
	 * If the testTransients parameter is set to <code>true</code>, transient members will be tested, otherwise they are
	 * ignored, as they are likely derived fields, and not part of the value of the <code>Object</code>.
	 * </p>
	 * <p>
	 * Static fields will not be included. Superclass fields will be appended up to and including the specified
	 * superclass. A null superclass is treated as java.lang.Object.
	 * </p>
	 * @param lhs <code>this</code> object
	 * @param rhs the other object
	 * @param testTransients whether to include transient fields
	 * @param reflectUpToClass the superclass to reflect up to (inclusive), may be <code>null</code>
	 * @param excludeFields array of field names to exclude from testing
	 * @return <code>true</code> if the two Objects have tested equals.
	 * @since 2.0
	 */
	public static boolean reflectionEquals(Object lhs, Object rhs, boolean testTransients, Class reflectUpToClass, String[] excludeFields) {
		throw new UnsupportedOperationException("reflectionEquals()");
	}

	// -------------------------------------------------------------------------

	/**
	 * <p>
	 * Adds the result of <code>super.equals()</code> to this builder.
	 * </p>
	 * @param superEquals the result of calling <code>super.equals()</code>
	 * @return EqualsBuilder - used to chain calls.
	 * @since 2.0
	 */
	public EqualsBuilder appendSuper(boolean superEquals) {
		if (isEquals == false) {
			return this;
		}
		isEquals = superEquals;
		return this;
	}

	// -------------------------------------------------------------------------

	/**
	 * <p>
	 * Test if two <code>Object</code>s are equal using their <code>equals</code> method.
	 * </p>
	 * @param lhs the left hand object
	 * @param rhs the right hand object
	 * @return EqualsBuilder - used to chain calls.
	 */
	public EqualsBuilder append(Object lhs, Object rhs) {
		if (isEquals == false) {
			return this;
		}
		if (lhs == rhs) {
			return this;
		}
		if (lhs == null || rhs == null) {
			this.setEquals(false);
			return this;
		}
		Class lhsClass = lhs.getClass();
		if (!lhsClass.isArray()) {
			// The simple case, not an array, just test the element
			isEquals = lhs.equals(rhs);
		} else if (lhs.getClass() != rhs.getClass()) {
			// Here when we compare different dimensions, for example: a boolean[][] to a boolean[]
			this.setEquals(false);
		}
		// 'Switch' on type of array, to dispatch to the correct handler
		// This handles multi dimensional arrays of the same depth
		else if (lhs instanceof long[]) {
			append((long[]) lhs, (long[]) rhs);
		} else if (lhs instanceof int[]) {
			append((int[]) lhs, (int[]) rhs);
		} else if (lhs instanceof short[]) {
			append((short[]) lhs, (short[]) rhs);
		} else if (lhs instanceof char[]) {
			append((char[]) lhs, (char[]) rhs);
		} else if (lhs instanceof byte[]) {
			append((byte[]) lhs, (byte[]) rhs);
		} else if (lhs instanceof double[]) {
			append((double[]) lhs, (double[]) rhs);
		} else if (lhs instanceof float[]) {
			append((float[]) lhs, (float[]) rhs);
		} else if (lhs instanceof boolean[]) {
			append((boolean[]) lhs, (boolean[]) rhs);
		} else {
			// Not an array of primitives
			append((Object[]) lhs, (Object[]) rhs);
		}
		return this;
	}

	/**
	 * <p>
	 * Test if two <code>long</code> s are equal.
	 * </p>
	 * @param lhs the left hand <code>long</code>
	 * @param rhs the right hand <code>long</code>
	 * @return EqualsBuilder - used to chain calls.
	 */
	public EqualsBuilder append(long lhs, long rhs) {
		if (isEquals == false) {
			return this;
		}
		isEquals = (lhs == rhs);
		return this;
	}

	/**
	 * <p>
	 * Test if two <code>int</code>s are equal.
	 * </p>
	 * @param lhs the left hand <code>int</code>
	 * @param rhs the right hand <code>int</code>
	 * @return EqualsBuilder - used to chain calls.
	 */
	public EqualsBuilder append(int lhs, int rhs) {
		if (isEquals == false) {
			return this;
		}
		isEquals = (lhs == rhs);
		return this;
	}

	/**
	 * <p>
	 * Test if two <code>short</code>s are equal.
	 * </p>
	 * @param lhs the left hand <code>short</code>
	 * @param rhs the right hand <code>short</code>
	 * @return EqualsBuilder - used to chain calls.
	 */
	public EqualsBuilder append(short lhs, short rhs) {
		if (isEquals == false) {
			return this;
		}
		isEquals = (lhs == rhs);
		return this;
	}

	/**
	 * <p>
	 * Test if two <code>char</code>s are equal.
	 * </p>
	 * @param lhs the left hand <code>char</code>
	 * @param rhs the right hand <code>char</code>
	 * @return EqualsBuilder - used to chain calls.
	 */
	public EqualsBuilder append(char lhs, char rhs) {
		if (isEquals == false) {
			return this;
		}
		isEquals = (lhs == rhs);
		return this;
	}

	/**
	 * <p>
	 * Test if two <code>byte</code>s are equal.
	 * </p>
	 * @param lhs the left hand <code>byte</code>
	 * @param rhs the right hand <code>byte</code>
	 * @return EqualsBuilder - used to chain calls.
	 */
	public EqualsBuilder append(byte lhs, byte rhs) {
		if (isEquals == false) {
			return this;
		}
		isEquals = (lhs == rhs);
		return this;
	}

	/**
	 * <p>
	 * Test if two <code>double</code>s are equal by testing that the pattern of bits returned by
	 * <code>doubleToLong</code> are equal.
	 * </p>
	 * <p>
	 * This handles NaNs, Infinities, and <code>-0.0</code>.
	 * </p>
	 * <p>
	 * It is compatible with the hash code generated by <code>HashCodeBuilder</code>.
	 * </p>
	 * @param lhs the left hand <code>double</code>
	 * @param rhs the right hand <code>double</code>
	 * @return EqualsBuilder - used to chain calls.
	 */
	public EqualsBuilder append(double lhs, double rhs) {
		if (isEquals == false) {
			return this;
		}
		isEquals = (lhs == rhs);
		return this;
	}

	/**
	 * <p>
	 * Test if two <code>float</code>s are equal byt testing that the pattern of bits returned by doubleToLong are
	 * equal.
	 * </p>
	 * <p>
	 * This handles NaNs, Infinities, and <code>-0.0</code>.
	 * </p>
	 * <p>
	 * It is compatible with the hash code generated by <code>HashCodeBuilder</code>.
	 * </p>
	 * @param lhs the left hand <code>float</code>
	 * @param rhs the right hand <code>float</code>
	 * @return EqualsBuilder - used to chain calls.
	 */
	public EqualsBuilder append(float lhs, float rhs) {
		if (isEquals == false) {
			return this;
		}
		isEquals = (lhs == rhs);
		return this;
	}

	/**
	 * <p>
	 * Test if two <code>booleans</code>s are equal.
	 * </p>
	 * @param lhs the left hand <code>boolean</code>
	 * @param rhs the right hand <code>boolean</code>
	 * @return EqualsBuilder - used to chain calls.
	 */
	public EqualsBuilder append(boolean lhs, boolean rhs) {
		if (isEquals == false) {
			return this;
		}
		isEquals = (lhs == rhs);
		return this;
	}

	/**
	 * <p>
	 * Performs a deep comparison of two <code>Object</code> arrays.
	 * </p>
	 * <p>
	 * This also will be called for the top level of multi-dimensional, ragged, and multi-typed arrays.
	 * </p>
	 * @param lhs the left hand <code>Object[]</code>
	 * @param rhs the right hand <code>Object[]</code>
	 * @return EqualsBuilder - used to chain calls.
	 */
	public EqualsBuilder append(Object[] lhs, Object[] rhs) {
		if (isEquals == false) {
			return this;
		}
		if (lhs == rhs) {
			return this;
		}
		if (lhs == null || rhs == null) {
			this.setEquals(false);
			return this;
		}
		if (lhs.length != rhs.length) {
			this.setEquals(false);
			return this;
		}
		for (int i = 0; i < lhs.length && isEquals; ++i) {
			append(lhs[i], rhs[i]);
		}
		return this;
	}

	/**
	 * <p>
	 * Deep comparison of array of <code>long</code>. Length and all values are compared.
	 * </p>
	 * <p>
	 * The method {@link #append(long, long)} is used.
	 * </p>
	 * @param lhs the left hand <code>long[]</code>
	 * @param rhs the right hand <code>long[]</code>
	 * @return EqualsBuilder - used to chain calls.
	 */
	public EqualsBuilder append(long[] lhs, long[] rhs) {
		if (isEquals == false) {
			return this;
		}
		if (lhs == rhs) {
			return this;
		}
		if (lhs == null || rhs == null) {
			this.setEquals(false);
			return this;
		}
		if (lhs.length != rhs.length) {
			this.setEquals(false);
			return this;
		}
		for (int i = 0; i < lhs.length && isEquals; ++i) {
			append(lhs[i], rhs[i]);
		}
		return this;
	}

	/**
	 * <p>
	 * Deep comparison of array of <code>int</code>. Length and all values are compared.
	 * </p>
	 * <p>
	 * The method {@link #append(int, int)} is used.
	 * </p>
	 * @param lhs the left hand <code>int[]</code>
	 * @param rhs the right hand <code>int[]</code>
	 * @return EqualsBuilder - used to chain calls.
	 */
	public EqualsBuilder append(int[] lhs, int[] rhs) {
		if (isEquals == false) {
			return this;
		}
		if (lhs == rhs) {
			return this;
		}
		if (lhs == null || rhs == null) {
			this.setEquals(false);
			return this;
		}
		if (lhs.length != rhs.length) {
			this.setEquals(false);
			return this;
		}
		for (int i = 0; i < lhs.length && isEquals; ++i) {
			append(lhs[i], rhs[i]);
		}
		return this;
	}

	/**
	 * <p>
	 * Deep comparison of array of <code>short</code>. Length and all values are compared.
	 * </p>
	 * <p>
	 * The method {@link #append(short, short)} is used.
	 * </p>
	 * @param lhs the left hand <code>short[]</code>
	 * @param rhs the right hand <code>short[]</code>
	 * @return EqualsBuilder - used to chain calls.
	 */
	public EqualsBuilder append(short[] lhs, short[] rhs) {
		if (isEquals == false) {
			return this;
		}
		if (lhs == rhs) {
			return this;
		}
		if (lhs == null || rhs == null) {
			this.setEquals(false);
			return this;
		}
		if (lhs.length != rhs.length) {
			this.setEquals(false);
			return this;
		}
		for (int i = 0; i < lhs.length && isEquals; ++i) {
			append(lhs[i], rhs[i]);
		}
		return this;
	}

	/**
	 * <p>
	 * Deep comparison of array of <code>char</code>. Length and all values are compared.
	 * </p>
	 * <p>
	 * The method {@link #append(char, char)} is used.
	 * </p>
	 * @param lhs the left hand <code>char[]</code>
	 * @param rhs the right hand <code>char[]</code>
	 * @return EqualsBuilder - used to chain calls.
	 */
	public EqualsBuilder append(char[] lhs, char[] rhs) {
		if (isEquals == false) {
			return this;
		}
		if (lhs == rhs) {
			return this;
		}
		if (lhs == null || rhs == null) {
			this.setEquals(false);
			return this;
		}
		if (lhs.length != rhs.length) {
			this.setEquals(false);
			return this;
		}
		for (int i = 0; i < lhs.length && isEquals; ++i) {
			append(lhs[i], rhs[i]);
		}
		return this;
	}

	/**
	 * <p>
	 * Deep comparison of array of <code>byte</code>. Length and all values are compared.
	 * </p>
	 * <p>
	 * The method {@link #append(byte, byte)} is used.
	 * </p>
	 * @param lhs the left hand <code>byte[]</code>
	 * @param rhs the right hand <code>byte[]</code>
	 * @return EqualsBuilder - used to chain calls.
	 */
	public EqualsBuilder append(byte[] lhs, byte[] rhs) {
		if (isEquals == false) {
			return this;
		}
		if (lhs == rhs) {
			return this;
		}
		if (lhs == null || rhs == null) {
			this.setEquals(false);
			return this;
		}
		if (lhs.length != rhs.length) {
			this.setEquals(false);
			return this;
		}
		for (int i = 0; i < lhs.length && isEquals; ++i) {
			append(lhs[i], rhs[i]);
		}
		return this;
	}

	/**
	 * <p>
	 * Deep comparison of array of <code>double</code>. Length and all values are compared.
	 * </p>
	 * <p>
	 * The method {@link #append(double, double)} is used.
	 * </p>
	 * @param lhs the left hand <code>double[]</code>
	 * @param rhs the right hand <code>double[]</code>
	 * @return EqualsBuilder - used to chain calls.
	 */
	public EqualsBuilder append(double[] lhs, double[] rhs) {
		if (isEquals == false) {
			return this;
		}
		if (lhs == rhs) {
			return this;
		}
		if (lhs == null || rhs == null) {
			this.setEquals(false);
			return this;
		}
		if (lhs.length != rhs.length) {
			this.setEquals(false);
			return this;
		}
		for (int i = 0; i < lhs.length && isEquals; ++i) {
			append(lhs[i], rhs[i]);
		}
		return this;
	}

	/**
	 * <p>
	 * Deep comparison of array of <code>float</code>. Length and all values are compared.
	 * </p>
	 * <p>
	 * The method {@link #append(float, float)} is used.
	 * </p>
	 * @param lhs the left hand <code>float[]</code>
	 * @param rhs the right hand <code>float[]</code>
	 * @return EqualsBuilder - used to chain calls.
	 */
	public EqualsBuilder append(float[] lhs, float[] rhs) {
		if (isEquals == false) {
			return this;
		}
		if (lhs == rhs) {
			return this;
		}
		if (lhs == null || rhs == null) {
			this.setEquals(false);
			return this;
		}
		if (lhs.length != rhs.length) {
			this.setEquals(false);
			return this;
		}
		for (int i = 0; i < lhs.length && isEquals; ++i) {
			append(lhs[i], rhs[i]);
		}
		return this;
	}

	/**
	 * <p>
	 * Deep comparison of array of <code>boolean</code>. Length and all values are compared.
	 * </p>
	 * <p>
	 * The method {@link #append(boolean, boolean)} is used.
	 * </p>
	 * @param lhs the left hand <code>boolean[]</code>
	 * @param rhs the right hand <code>boolean[]</code>
	 * @return EqualsBuilder - used to chain calls.
	 */
	public EqualsBuilder append(boolean[] lhs, boolean[] rhs) {
		if (isEquals == false) {
			return this;
		}
		if (lhs == rhs) {
			return this;
		}
		if (lhs == null || rhs == null) {
			this.setEquals(false);
			return this;
		}
		if (lhs.length != rhs.length) {
			this.setEquals(false);
			return this;
		}
		for (int i = 0; i < lhs.length && isEquals; ++i) {
			append(lhs[i], rhs[i]);
		}
		return this;
	}

	/**
	 * <p>
	 * Returns <code>true</code> if the fields that have been checked are all equal.
	 * </p>
	 * @return boolean
	 */
	public boolean isEquals() {
		return this.isEquals;
	}

	/**
	 * Sets the <code>isEquals</code> value.
	 * @param isEquals The value to set.
	 * @since 2.1
	 */
	protected void setEquals(boolean isEquals) {
		this.isEquals = isEquals;
	}

	/**
	 * Reset the EqualsBuilder so you can use the same object again
	 * @since 2.5
	 */
	public void reset() {
		this.isEquals = true;
	}
}
